Exhibit 10.1


 


REGISTRATION RIGHTS AGREEMENT


 


This Registration Rights Agreement (this
“Agreement”) is made and entered into as of July 20, 2018 by and between ClearSign Combustion Corporation (the
“Company”), and CLIRSPV, LLC, a Delaware limited liability company (the “Purchaser”).


 


RECITAL


 


This Agreement is made pursuant to the Stock
Purchase Agreement, dated as of July 12, 2018, between the Company and the Purchaser (the “Purchase Agreement”).


 


AGREEMENT


 


NOW, THEREFORE, IN CONSIDERATION of
the mutual covenants contained in this Agreement, and for other good and valuable consideration the receipt and adequacy of which
are hereby acknowledged, the Company and the Purchaser agree as follows:


 


SECTION 1.


DEFINITIONS


 


Capitalized terms used and not otherwise
defined herein that are defined in the Purchase Agreement shall have the meanings given such terms in the Purchase Agreement. 
As used in this Agreement, the following terms shall have the respective meanings set forth in this Section 1:


 


“Advice” shall have the
meaning set forth in Section 7(b).


 


“Affiliate” means, with
respect to any Person, any other Person that, directly or indirectly through one or more intermediaries, Controls, is controlled
by or is under common control with such Person, as such terms are used in and construed under Rule 405 under the Securities
Act.


  


“Control” (including
the terms “controlling”, “controlled by” or “under common control with”) means the possession,
direct or indirect, of the power to direct or cause the direction of the management and policies of a Person, whether through the
ownership of voting securities, by contract or otherwise.


 


“Commission” means the
United States Securities and Exchange Commission, or any successor entity or entities, including, if applicable, the staff of the
Commission.


 


“Common Stock” means
the common stock, par value $0.0001 per share, of the Company.


 


“Effectiveness Date”
means: (a) with respect to the Initial Registration Statement required to be filed hereunder, the date of that is six months
after the date of this Agreement and (b) with respect to any additional Registration Statements which may be required pursuant
to Section 2, the earlier to occur of (i) the 90th day following the date on which the Company first knows, or reasonably
should have known, that such additional Registration Statement is required under such Section (or the 120th day following
such date in the event such additional Registration Statement is reviewed by the Commission) and (ii) the 5th Trading
Day after the date the Company is notified (orally or in writing, whichever is earlier) by the Commission that such Registration
Statement will not be “reviewed” or will not be subject to further review. If the Effectiveness Date falls on a Saturday,
Sunday or other date that the Commission is closed for business, the Effectiveness Date shall be extended to the next day on which
the Commission is open for business.  The Effectiveness Date for a Registration Statement shall be extended without default
hereunder in the event that the Company’s failure to obtain the effectiveness of the Registration Statement on a timely basis
results from the failure of the Holder to timely provide the Company with information requested by the Company and necessary
to complete the Registration Statement in accordance with the requirements of the Securities Act (in which the Effectiveness Date
would be extended with respect to Registrable Securities held by such Holder).


 






     


     


    

 


“Effectiveness Period”
shall have the meaning set forth in Section 2(a).


 


“Exchange Act” means
the Securities Exchange Act of 1934, as amended.


 


“Filing Date” means:
(a) with respect to the Initial Registration Statement, the 3 month anniversary of the Closing Date, and (b) with respect
to any additional Registration Statements that may be required pursuant to Section 2 hereof, the 45th day following the
date on which the Company first knows, or reasonably should have known, that such additional Registration Statement is required
under such Section.


 


“Holder” or “Holders”
means a holder from time to time of Registrable Securities, but only if such holder is the Purchaser or any assignee thereof in
accordance with Section 7(j).


 


“Indemnified Party” shall
have the meaning set forth in Section 6(c).


 


“Indemnifying Party”
shall have the meaning set forth in Section 6(c).


 


“Initial Registration Statement”
shall mean the initial Registration Statement required to be filed to cover the resale by the Purchaser of the Registrable Securities
pursuant to Section 2(a).


 


“Losses” shall have the
meaning set forth in Section 6(a).


  


“Person” means an individual
or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint
stock company, government (or an agency or subdivision thereof) or other entity of any kind.


  


“Proceeding” means an
action, claim, suit, investigation or proceeding (including, without limitation, an investigation or partial proceeding, such as
a deposition), whether commenced or threatened.


 


“Prospectus” means the
prospectus included in a Registration Statement (including, without limitation, a prospectus that includes any information previously
omitted from a prospectus filed as part of an effective registration statement in reliance upon Rule 430A or Rule 430B
promulgated by the Commission pursuant to the Securities Act), as amended or supplemented by any prospectus supplement, with respect
to the terms of the offering of any portion of the Registrable Securities covered by a Registration Statement, and all other amendments
and supplements to the Prospectus, including post-effective amendments, and all material incorporated by reference or deemed to
be incorporated by reference in such Prospectus.


 


“Reduction Securities”
shall have the meaning set forth in Section 2(b).


 


“Registrable Securities”
means (i) the Shares issued pursuant to the Purchase Agreement including any shares issued pursuant to the Purchase Right
and, in the case of the Participation Right only, so long as the shares purchased by other investors in the offering subject to
the Participation Right are also required to be registered and (ii) any other shares of Common Stock issued as (or issuable
upon conversion or exercise of any warrant, right or other security which is issued as) a dividend or other distribution with respect
to, in exchange for or in replacement of the Shares; provided, however, that any such Registrable Securities shall cease to be
Registrable Securities (and the Company shall not be required to maintain the effectiveness of any, or file another, Registration
Statement hereunder with respect thereto) for so long as (a) a Registration Statement with respect to the sale of such Registrable
Securities is declared effective by the Commission under the Securities Act and such Registrable Securities have been disposed
of by the Holder in accordance with such effective Registration Statement, (b) such Registrable Securities have been previously
sold in accordance with Rule 144, (c) such Registrable Securities become eligible for resale without volume or manner-of-sale
restrictions and without current public information pursuant to Rule 144, as reasonably determined by the Company, based upon
the advice of counsel to the Company, (d) such Registrable Securities have been sold, transferred or otherwise disposed of
by a Person in a transaction in which its rights under this Agreement were not assigned in accordance with Section 7(j), or
(e) such Registrable Securities cease to be outstanding.


 






     


     


    

 


“Registration Statement”
means each of the following: (i) an initial registration statement which is required to register the resale of the Registrable
Securities, and (ii) each additional registration statement, if any, contemplated by Section 2, and including, in each
case, the Prospectus, amendments and supplements to each such registration statement or Prospectus, including pre- and post-effective
amendments, all exhibits thereto, and all material incorporated by reference or deemed to be incorporated by reference in such
registration statement.


 


“Rule 144” means
Rule 144 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time,
or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.


 


“Rule 415” means
Rule 415 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time,
or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.


  


“Rule 424” means
Rule 424 promulgated by the Commission pursuant to the Securities Act, as such Rule may be amended from time to time,
or any similar rule or regulation hereafter adopted by the Commission having substantially the same effect as such Rule.


 


“SEC Guidance” means
(i) any publicly-available written guidance of the Commission staff, (ii) any oral guidance, comments, requirements or
requests of the Commission staff, in each case given or directed specifically to the Company, and (iii) the Securities Act.


 


“Securities Act” means
the Securities Act of 1933, as amended.


 


“Shares” shall have the
meaning set forth in the Purchase Agreement and shall include shares of Common Stock purchased by the Purchaser pursuant to the
Purchase Right and the Participation Right, and, in the case of the Participation Right only, so long as the shares purchased by
other investors in the offering subject to the Participation Right are also required to be registered.


 


“Trading Day” means any
day on which the Common Stock is traded on the Nasdaq Capital Market, or, if the Nasdaq Capital Market is not the principal trading
market for the Common Stock, then on the principal securities exchange or securities market on which the Common Stock is then traded.


 


“Transaction Documents”
shall have the meaning set forth in the Purchase Agreement.


  


SECTION 2.


REGISTRATION


 


(a)   On or prior to each Filing Date, the Company shall prepare and file with the Commission a Registration Statement covering the resale
of all of the Registrable Securities that are not then registered on an existing and effective Registration Statement for an offering
to be made on a continuous basis pursuant to Rule 415.  The Registration Statement filed hereunder shall be on Form S-3
(except if the Company is not then eligible to register for resale the Registrable Securities on Form S-3, in which case such
registration shall be on another appropriate form in accordance herewith) and shall contain (except if otherwise required pursuant
to written comments received from the Commission upon a review of such Registration Statement) the “Plan of Distribution”
in substantially the form attached hereto as Annex A.  The Company shall use its commercially reasonable efforts to
cause a Registration Statement filed under this Agreement to be declared effective under the Securities Act no later than the Effectiveness
Date for such Registration Statement, and shall, subject Section 7(b) hereof, use its commercially reasonable efforts
to keep the Registration Statement continuously effective under the Securities Act until the date on which all securities under
such Registration Statement have ceased to be Registrable Securities (the “Effectiveness Period”).  It
is agreed and understood that the Company shall, from time to time, be obligated to file one or more additional Registration Statements
to cover any Registrable Securities which are not registered for resale pursuant to a pre-existing Registration Statement.


 






     


     


    

 


(b)   Notwithstanding
anything contained herein to the contrary, in the event that the Commission limits the amount of Registrable Securities that may
be included and sold by the Holder in any Registration Statement, including the Initial Registration Statement, pursuant to Rule 415
or any other basis (and notwithstanding that the Company used commercially reasonable efforts to advocate with the Commission where
practicable for the registration of all or a greater number of Registrable Securities), the Company may reduce the number of Registrable
Securities included in such Registration Statement on behalf of such Holder in whole or in part (in case of an exclusion as to
a portion of such Registrable Securities, such portion shall be allocated pro rata among multiple Holders in proportion to the
respective numbers of Registrable Securities represented by Shares requested to be registered by each such Holder over the total
amount of Registrable Securities represented by Shares) (such Registrable Securities, the “Reduction Securities”). 
Any reduction of Registrable Securities pursuant to this Section 2(b) shall occur only after all securities that are
not Registrable Securities, if any, are first removed from such Registration Statement where permitted under contractual arrangements
between the Company and the holders of such other securities (provided that the Company first uses commercially reasonable efforts
(which efforts shall not require the Company to pay money or issue additional securities to the holders) to obtain waivers under
such contractual arrangements of stockholders’ rights to have such securities included in such Registration Statement). 
In such event, the Company shall give the Holder prompt notice of the number of such Reduction Securities excluded and the Company
will not be liable for any damages under this Agreement in connection with the exclusion of such Reduction Securities.  The
Company shall use its commercially reasonable efforts at the first opportunity that is permitted by the Commission to register
for resale the Reduction Securities.  Such new Registration Statement shall be on Form S-3 (except if the Company is
not then eligible to register for resale the Reduction Securities on Form S-3, in which case such registration shall be on
another appropriate form for such purpose) and shall contain (except if otherwise required pursuant to written comments received
from the Commission upon a review of such Registration Statement) the “Plan of Distribution” in substantially the form
attached hereto as Annex A.  The Company shall use its commercially reasonable efforts to cause each such Registration
Statement to be declared effective under the Securities Act as soon as possible but, in any event, no later than the Effectiveness
Date, and shall use its commercially reasonable efforts to keep such Registration Statement continuously effective under the Securities
Act during the entire Effectiveness Period, subject to Section 7(b) hereof.


 


(c)   No
Holder shall be named as an “underwriter” in any Registration Statement without such Holder’s prior written consent,
except if required pursuant to written comments received from the Commission upon a review of such Registration Statement; provided,
however, that prior to naming a Holder as an underwriter in any Registration Statement, (i) the Company shall use its commercially
reasonable efforts to advocate with the Commission against naming such Holder as an underwriter in accordance with Commission rules and
regulations and SEC Guidance and (ii) if, despite the Company’s commercially reasonable efforts to advocate with the
Commission against naming such Holder as an underwriter, the Commission continues to require that such Holder be named as an underwriter
in any Registration Statement, such Holder shall have the right (but not the obligation), prior to being so named, without any
penalty to the Company, to either (A) remove itself from such Registration Statement or (B) reduce its number of Registrable
Securities included in such Registration Statement such that it shall no longer be required to be named as an underwriter in such
Registration Statement.


 


(d)   Unless
contractually obligated to do so (provided that the Company first uses commercially reasonable efforts (which efforts shall not
require the Company to pay money or issue additional securities to the holders) to obtain waivers under such contractual arrangements
of stockholders’ rights to have such securities included in such Registration Statement), in no event shall the Company include
any securities other than the Registrable Securities on any Registration Statement without the prior written consent of Holders
of a majority of the Registrable Securities.


 


(e)   The
disposition of Registrable Securities from any Registration Statement may occur in one or more underwritten offerings, block transactions,
broker transactions, at-market transactions or in such other manner or manners as may be specified by the Holders in accordance
with applicable law.


 


(f)    In
the event that Form S-3 is not available for the registration of the resale of Registrable Securities hereunder, the
Company shall (i) register the resale of the Registrable Securities on another appropriate form and (ii) undertake to
register the Registrable Securities on Form S-3 promptly after such form is available, provided that the Company shall
maintain the effectiveness of the Registration Statement then in effect until such time as a Registration Statement on Form S-3
covering the Registrable Securities has been declared effective by the Commission.


 






     


     


    

 


SECTION 3.


REGISTRATION PROCEDURES


 


In connection with the Company’s registration
obligations hereunder, the Company shall:


 


(a)   Not less than three Trading Days prior to the filing of a Registration Statement or any related Prospectus or any amendment or
supplement thereto, the Company shall furnish to the Holder copies of all such documents proposed to be filed (other than those
incorporated by reference).  Notwithstanding the foregoing, the Company shall not be required to furnish to the Holder any
prospectus supplement being prepared and filed solely to name new or additional selling securityholders unless such Holder is named
in such prospectus supplement.  In addition, in the event that any Registration Statement is on a form which does not permit
incorporation by reference), the Company shall not be required to furnish to the Holder any prospectus supplement containing information
included in a report or proxy statement filed under the Exchange Act that would be incorporated by reference in such Registration
Statement if such Registration Statement were on Form S-3 (or other form which permits incorporation by reference). 
The Company shall duly consider any comments made by the Holder and received by the Company not later than two Trading Days prior
to the filing of the Registration Statement, but shall not be required to accept any such comments to which it reasonably objects.


 


(b)   (i) 
Prepare and file with the Commission such amendments, including post-effective amendments, to each Registration Statement and the
Prospectus used in connection therewith as may be necessary to keep such Registration Statement continuously effective as to the
applicable Registrable Securities for its Effectiveness Period and prepare and file with the Commission such additional Registration
Statements in order to register for resale under the Securities Act all of the Registrable Securities; (ii) cause the related
Prospectus to be amended or supplemented by any required Prospectus supplement, and as so supplemented or amended to be filed pursuant
to Rule 424; (iii) respond as promptly as reasonably possible to any comments received from the Commission with respect
to each Registration Statement or any amendment thereto and, as promptly as reasonably possible notify the Holder of such comments
and, upon the request of such Holder, provide the Holder true and complete copies of all correspondence from and to the Commission
relating to such Registration Statement that pertains to the Holder as a Selling Stockholder; and (iv) comply in all material
respects with the provisions of the Securities Act and the Exchange Act with respect to the Registration Statements and the disposition
of all Registrable Securities covered by each Registration Statement.


 


(c)   Notify the Holder as promptly as reasonably possible (and, in the case of (i)(A) below, not less than three Trading Days prior
to such filing) and (if requested by any such Person) confirm such notice in writing no later than one Trading Day following the
day: (i)(A) when a Prospectus or any prospectus supplement (but only to the extent notice is required under Section 3(a) above)
or post-effective amendment to a Registration Statement is proposed to be filed; (B) when the Commission notifies the Company
whether there will be a “review” of such Registration Statement and whenever the Commission comments in writing on
such Registration Statement (in which case the Company shall provide true and complete copies thereof and all written responses
thereto to each of the Holders that pertain to such Holder as a Selling Stockholder or to the Plan of Distribution upon the request
of such Holder); and (C) with respect to each Registration Statement or any post-effective amendment, when the same has been
declared effective; (ii) of any request by the Commission or any other Federal or state governmental authority for amendments
or supplements to a Registration Statement or Prospectus or for additional information that pertains to the Holder as a Selling
Stockholder or the Plan of Distribution; (iii) of the issuance by the Commission of any stop order suspending the effectiveness
of a Registration Statement covering any or all of the Registrable Securities or the initiation of any Proceedings for that purpose;
(iv) of the receipt by the Company of any notification with respect to the suspension of the qualification or exemption from
qualification of any of the Registrable Securities for sale in any jurisdiction, or the initiation or threatening of any Proceeding
for such purpose; (v) of the occurrence of any event or passage of time that makes the financial statements included or incorporated
by reference in a Registration Statement ineligible for inclusion or incorporation by reference therein or any statement made in
such Registration Statement or Prospectus or any document incorporated or deemed to be incorporated therein by reference untrue
in any material respect or that requires any revisions to such Registration Statement, Prospectus or other documents so that, in
the case of such Registration Statement or the Prospectus, as the case may be, it will not contain any untrue statement of a material
fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in light of
the circumstances under which they were made, not misleading; and (vi) of the occurrence or existence of any pending corporate
development with respect to the Company that the Company in good faith believes may be material and that, in the determination
of the Company, makes it not in the best interest of the Company to allow continued availability of a Registration Statement or
Prospectus.


 






     


     


    

 


(d)   Use its reasonable best efforts to avoid the issuance of, or, if issued, obtain the withdrawal of (i) any order suspending
the effectiveness of a Registration Statement, or (ii) any suspension of the qualification (or exemption from qualification)
of any of the Registrable Securities for sale in any jurisdiction, at the earliest practicable moment.


 


(e)   Furnish to the Holder, without charge, at least one conformed copy of each Registration Statement and each amendment thereto and
all exhibits to the extent reasonably requested by such Person (including those previously furnished or incorporated by reference)
promptly after the filing of such documents with the Commission; provided, that the Company shall have no obligation to
provide any document pursuant to this clause that is available on the EDGAR system.


 


(f)    Promptly deliver to the Holder, without charge, as many copies of each Prospectus or Prospectuses (including each form of prospectus)
and each amendment or supplement thereto as such Person may reasonably request.  Subject to Section 7(b) hereof,
the Company hereby consents to the use of such Prospectus and each amendment or supplement thereto by each of the selling Holders
in connection with the offering and sale of the Registrable Securities covered by such Prospectus and any amendment or supplement
thereto.


 


(g)   Prior to any public offering of Registrable Securities, use its commercially reasonable efforts to register or qualify or cooperate
with the selling Holder in connection with the registration or qualification (or exemption from such registration or qualification)
of such Registrable Securities for offer and sale under the securities or Blue Sky laws of those jurisdictions within the United
States as such Holder reasonably requests in writing to keep each such registration or qualification (or exemption therefrom) effective
during the Effectiveness Period and to do any and all other acts or things necessary or advisable to enable the disposition in
such jurisdictions of the Registrable Securities covered by the Registration Statements; provided, that the Company shall
not be required to qualify generally to do business in any jurisdiction where it is not then so qualified or subject the Company
to any material tax in any such jurisdiction where it is not then so subject.


 


(h)   Cooperate with the Holder to facilitate the timely preparation and delivery of certificates representing Registrable Securities
to be delivered to a transferee pursuant to the Registration Statements, which certificates shall be free, to the extent permitted
by the Purchase Agreement, of all restrictive legends, and to enable such Registrable Securities to be in such denominations and
registered in such names as the Holder may request.


 


(i)    Upon the occurrence of any event contemplated by Section 3(c)(v), as promptly as reasonably possible, prepare a supplement
or amendment, including a post-effective amendment, to the affected Registration Statements or a supplement to the related Prospectus
or any document incorporated or deemed to be incorporated therein by reference, and file any other required document so that, as
thereafter delivered, no Registration Statement nor any Prospectus will contain an untrue statement of a material fact or omit
to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances
under which they were made, not misleading.


 


(j)    The Company may require the selling Holder to furnish to the Company a certified statement as to the number of shares of Common
Stock beneficially owned by such Holder and any Affiliate thereof, the natural persons, if any, thereof that have voting and dispositive
control over the shares and any other information with respect to such Holder as the Commission requests.


  






     


     


    

 


(k)   Make available at reasonable times for inspection by any Holder, any managing underwriter participating in any disposition of such
Registrable Securities pursuant to a Registration Statement, Holders’ legal counsel and any attorney, accountant or other
agent retained by any such Holder or any managing underwriter (each, an “Inspector” and collectively, the “Inspectors”),
all financial and other records, pertinent corporate documents and properties of the Company and its subsidiaries (collectively,
the “Records”) as shall be reasonably necessary to enable them to exercise their due diligence responsibility,
and cause the Company’s and its subsidiaries’ officers, directors and employees, and the independent public accountants
of the Company, to supply all information reasonably requested by any such Inspector in connection with such Registration Statement.
Notwithstanding the foregoing, Records and other information that the Company determines, in good faith, to be confidential and
which it notifies the Inspectors are confidential shall not be disclosed by the Inspectors or used for any purpose other than as
necessary or appropriate for the purpose of such inspection (and the Inspectors shall confirm their agreement in writing in advance
to the Company if the Company shall so request) unless (i) the disclosure of such Records is necessary, in the Company’s
judgment, to avoid or correct a misstatement or omission in the Registration Statement, (ii) the release of such Records is
ordered pursuant to a subpoena or other order from a court of competent jurisdiction after exhaustion of all appeals therefrom
or (iii) the information in such Records was known to the Inspectors on a non-confidential basis prior to its disclosure by
the Company or has been made generally available to the public. Each Holder agrees that it shall promptly, upon learning that disclosure
of such Records is sought in a court of competent jurisdiction, give notice to the Company and allow the Company, at the Company’s
expense, to undertake appropriate action to prevent disclosure of the Records deemed confidential, and such Holder shall reasonably
cooperate with the Company in connection therewith.


 


(l)    If
such sale is pursuant to an underwritten offering, (i) obtain “comfort” letters dated the pricing and closing
dates of such offering under the underwriting agreement from the Company’s independent public accountants in customary form
and covering such matters of the type customarily covered by “comfort” letters as Holders’ legal counsel or the
managing underwriter reasonably requests; (ii) enter into a customary underwriting agreement with the underwriter containing
customary representations and warranties, covenants and legal opinions addressed to the underwriters; (iii) take other such
actions as reasonably required in order to expedite or facilitate the disposition of such Registrable Securities, including causing
its officers to participate in “road shows” and other information meetings organized by the underwriters, if applicable,
of reasonable and customary duration and frequency (but not to exceed three days in each instance); or (iv) deliver such documents
and certificates as may be reasonably requested and as are customarily delivered in similar offerings.


 


(m)  Comply with all applicable rules and regulations of the SEC, and make generally available to its security holders, as soon
as reasonably practicable but no later than fifteen (15) months after the effective date of the Registration Statement, an earnings
statement covering a period of twelve (12) months beginning after the effective date of the Registration Statement, in a manner
which satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder.


 


(n)   Cause all such Registrable Securities to be listed on each securities exchange on which similar securities issued by the Company
are then listed.


  


(o)   Provide reasonable cooperation to each seller of Registrable Securities and each underwriter participating in the disposition of
such Registrable Securities and their respective counsel in connection with any filings required to be made with the Financial
Industry Regulatory Authority (“FINRA”) pursuant to FINRA Rule 5110 as requested by such Holder.


 


SECTION 4.


HOLDER’S OBLIGATIONS


 


The Holder agrees, by acquisition of the
Registrable Securities, that the Holder shall not be entitled to sell any of such Registrable Securities pursuant to a Registration
Statement or to receive a Prospectus relating thereto, unless such Holder has furnished the Company with all material information
required to be set forth in the Purchaser Questionnaire and Selling Stockholder Questionnaire attached hereto as Annex B. 
Any sale of any Registrable Securities by any Holder shall constitute a representation and warranty by such Holder that the information
regarding such Holder is as set forth in the Prospectus delivered by such Holder in connection with such disposition, and that
such Prospectus does not as of the time of such sale contain any untrue statement of a material fact regarding such Holder or omit
to state any material fact regarding such Holder necessary to make the statements in such Prospectus, in the light of the circumstances
under which they were made, not misleading, solely to the extent such facts are based upon information regarding such Holder furnished
in writing to the Company by such Holder for use in such Prospectus.


 




     


     


    

 


SECTION 5.


REGISTRATION EXPENSES


 


All fees and expenses incident to the Company’s
performance of or compliance with its obligations under this Agreement shall be borne by the Company whether or not any Registrable
Securities are sold pursuant to a Registration Statement.  The fees and expenses referred to in the foregoing sentence shall
include, without limitation, (i) all registration and filing fees (including, without limitation, fees and expenses (A) with
respect to filings required to be made with the principal trading market on which the Common Stock is then listed for trading,
(B) in compliance with applicable state securities or Blue Sky laws) and (C) if not previously paid by the Company in
connection with an issuer filing, with respect to any filing that may be required to be made by any broker through which a Holder
intends to make sales of Registrable Securities with FINRA pursuant to FINRA Rule 5110, so long as the broker is receiving
no more than a customary brokerage commission in connection with such sale, (ii) printing expenses (including, without limitation,
expenses of printing certificates for Registrable Securities and of printing prospectuses if the printing of prospectuses is reasonably
requested by the holders of a majority of the Registrable Securities included in the Registration Statement), (iii) messenger,
telephone and delivery expenses, (iv) reasonable fees and disbursements of counsel for the Company, (v) Securities Act
liability insurance, if the Company so desires such insurance, and (vi) reasonable fees and expenses of all other Persons
retained by the Company in connection with the consummation of the transactions contemplated by this Agreement.  In addition,
the Company shall be responsible for all of its internal expenses incurred in connection with the consummation of the transactions
contemplated by this Agreement (including, without limitation, all salaries and expenses of its officers and employees performing
legal or accounting duties), the expense of any annual audit and the fees and expenses incurred in connection with the listing
of the Registrable Securities on any securities exchange as required hereunder.  The Holder shall bear the cost of all underwriting
discounts and selling commissions associated with any sale of Registrable Securities and shall pay all of its own costs and expenses,
including, without limitation, all fees and disbursements to counsel (and any other advisors) of the Holder and any stock transfer
taxes.  In no event shall the Company be responsible for any broker or similar commissions of any Holder.


 


SECTION 6.


INDEMNIFICATION


 


(a)   Indemnification by the Company.  The Company shall, notwithstanding any termination of this Agreement, indemnify
and hold harmless the Holder, the officers, directors, agents, partners, members, stockholders and employees of such Holder, each
Person who controls such Holder (within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange
Act) and the officers, directors, agents, partners, members, stockholders and employees of each such controlling Person, to the
fullest extent permitted by applicable law, from and against any and all losses, claims, damages, liabilities, costs (including,
without limitation, reasonable costs of preparation and reasonable attorneys’ fees) and expenses (collectively, “Losses”),
as incurred, arising out of or relating to any untrue or alleged untrue statement of a material fact contained in any Registration
Statement, any Prospectus or any form of prospectus or in any amendment or supplement thereto (it being understood that the Holder
has approved Annex A hereto for this purpose), or arising out of or relating to any omission or alleged omission of a material
fact required to be stated therein or necessary to make the statements therein (in the case of any Prospectus or form of prospectus
or supplement thereto, in light of the circumstances under which they were made) not misleading, except to the extent, but only
to the extent, that (1) such untrue statements, alleged untrue statements, omissions or alleged omissions are based solely
upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the
extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities
and was reviewed and expressly approved in writing by such Holder expressly for use in the Registration Statement, such Prospectus
or such form of Prospectus or in any amendment or supplement thereto (it being understood that the Holder has approved Annex
A hereto for this purpose) or (2) in the case of an occurrence of an event of the type specified in Section 3(c)(ii)-(v),
the use by such Holder of an outdated or defective Prospectus after the Company has validly notified such Holder in writing (in
accordance with Section 7(b) below) that the Prospectus is outdated or defective and prior to the receipt by such Holder
of an Advice (as defined below) or an amended or supplemented Prospectus, but only if and to the extent that following the receipt
of the Advice or the amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected. 
The Company shall notify the Holder promptly of the institution, threat or assertion of any Proceeding of which the Company is
aware in connection with the transactions contemplated by this Agreement.


 






     


     


    

 


(b)   Indemnification by Holder.  The Holder shall, notwithstanding any termination of this Agreement, severally and
not jointly, indemnify and hold harmless the Company, its directors, officers, agents and employees, each Person who controls the
Company (within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act), and the directors,
officers, agents, partners, members, stockholders or employees of such controlling Persons, to the fullest extent permitted by
applicable law, from and against all Losses, as incurred, arising solely out of or based solely upon: (x) for so long as the
prospectus delivery requirements of the Securities Act apply to sales by such Holder, such Holder’s failure to comply with
the prospectus delivery requirements of the Securities Act or (y) any untrue statement of a material fact contained in any
Registration Statement, any Prospectus, or any form of prospectus, or in any amendment or supplement thereto, or arising solely
out of or based solely upon any omission of a material fact required to be stated therein or necessary to make the statements therein
(in the case of any Prospectus, or any form of prospectus or supplement thereto, in light of the circumstances under which they
were made) not misleading to the extent, but only to the extent that, (1) such untrue statements or omissions are based solely
upon information regarding such Holder furnished in writing to the Company by such Holder expressly for use therein, or to the
extent that such information relates to such Holder or such Holder’s proposed method of distribution of Registrable Securities
and was reviewed and expressly approved in writing by such Holder expressly for use in the Registration Statement, such Prospectus
or such form of Prospectus or in any amendment or supplement thereto (it being understood that the Holder has approved Annex A
hereto for this purpose) or (2) in the case of an occurrence of an event of the type specified in Section 3(c)(ii)-(v),
the use by such Holder of an outdated or defective Prospectus after the Company has validly notified such Holder in writing (in
accordance with Section 7(b) below) that the Prospectus is outdated or defective and prior to the receipt by such Holder of an
Advice or an amended or supplemented Prospectus, but only if and to the extent that following the receipt of the Advice or the
amended or supplemented Prospectus the misstatement or omission giving rise to such Loss would have been corrected.  In no
event shall the liability of any selling Holder hereunder be greater in amount than the dollar amount of the net proceeds received
by such Holder upon the sale of the Registrable Securities giving rise to such indemnification obligation.


 


(c)   Conduct of Indemnification Proceedings.  If any Proceeding shall be brought or asserted against any Person entitled
to indemnity hereunder (an “Indemnified Party”), such Indemnified Party shall promptly notify the Person from
whom indemnity is sought (the “Indemnifying Party”) in writing, and the Indemnifying Party shall assume the
defense thereof, including the employment of counsel reasonably satisfactory to the Indemnified Party and the payment of all fees
and expenses incurred in connection with defense thereof; provided, that the failure of any Indemnified Party to give such notice
shall not relieve the Indemnifying Party of its obligations or liabilities pursuant to this Agreement, except (and only) to the
extent that it shall be finally determined by a court of competent jurisdiction (which determination is not subject to appeal or
further review) that such failure shall have proximately and materially adversely prejudiced the Indemnifying Party.


 


An Indemnified Party shall have the right
to employ separate counsel in any such Proceeding and to participate in the defense thereof, but the fees and expenses of such
counsel shall be at the expense of such Indemnified Party or Parties unless:  (1) the Indemnifying Party has agreed in
writing to pay such fees and expenses; (2) the Indemnifying Party shall have failed promptly to assume the defense of such
Proceeding and to employ counsel reasonably satisfactory to such Indemnified Party in any such Proceeding; or (3) the named
parties to any such Proceeding (including any impleaded parties) include both such Indemnified Party and the Indemnifying Party,
and such Indemnified Party shall have been advised by counsel that a conflict of interest is likely to exist if the same counsel
were to represent such Indemnified Party and the Indemnifying Party (in which case, if such Indemnified Party notifies the Indemnifying
Party in writing that it elects to employ separate counsel at the expense of the Indemnifying Party, the Indemnifying Party shall
not have the right to assume the defense thereof and such counsel shall be at the expense of the Indemnifying Party); provided,
that the Indemnifying Party shall not be liable for the fees and expenses of more than one separate firm of attorneys at any time
for all Indemnified Parties pursuant to this Section 6(c).  The Indemnifying Party shall not be liable for any settlement
of any such Proceeding effected without its written consent, which consent shall not be unreasonably withheld.  No Indemnifying
Party shall, without the prior written consent of the Indemnified Party, effect any settlement of any pending Proceeding in respect
of which any Indemnified Party is a party, unless such settlement includes an unconditional release of such Indemnified Party from
all liability on claims that are the subject matter of such Proceeding. Each Indemnified Party shall furnish such information regarding
itself or the claim in question as an Indemnifying Party may reasonably request in writing and as shall be reasonably required
in connection with defense of such claim and litigation resulting therefrom.


 






     


     


    

 


All fees and expenses of the Indemnified Party
(including reasonable fees and expenses to the extent incurred in connection with investigating or preparing to defend such Proceeding
in a manner not inconsistent with this Section) shall be paid to the Indemnified Party, as incurred, within ten Trading Days of
written notice thereof to the Indemnifying Party (regardless of whether it is ultimately determined that an Indemnified Party is
not entitled to indemnification hereunder; provided, that the Indemnifying Party may require such Indemnified Party to undertake
to reimburse all such fees and expenses to the extent it is finally judicially determined that such Indemnified Party is not entitled
to indemnification hereunder).


 


(d)   Contribution.  If a claim for indemnification under Section 6(a) or Section 6(b) is unavailable
to an Indemnified Party (by reason of public policy or otherwise), then each Indemnifying Party, in lieu of indemnifying such Indemnified
Party, shall contribute to the amount paid or payable by such Indemnified Party as a result of such Losses, in such proportion
as is appropriate to reflect the relative fault of the Indemnifying Party and Indemnified Party in connection with the actions,
statements or omissions that resulted in such Losses as well as any other relevant equitable considerations.  The relative
fault of such Indemnifying Party and Indemnified Party shall be determined by reference to, among other things, whether any action
in question, including any untrue or alleged untrue statement of a material fact or omission or alleged omission of a material
fact, has been taken or made by, or relates to information supplied by, such Indemnifying Party or Indemnified Party, and the parties’
relative intent, knowledge, access to information and opportunity to correct or prevent such action, statement or omission. 
The amount paid or payable by a party as a result of any Losses shall be deemed to include, subject to the limitations set forth
in Section 6(c), any reasonable attorneys’ or other reasonable fees or expenses incurred by such party in connection
with any Proceeding to the extent such party would have been indemnified for such fees or expenses if the indemnification provided
for in this Section was available to such party in accordance with its terms.


 


The parties hereto agree that it would not
be just and equitable if contribution pursuant to this Section 6(d) were determined by pro rata allocation or by any
other method of allocation that does not take into account the equitable considerations referred to in the immediately preceding
paragraph.  Notwithstanding the provisions of this Section 6(d), no Holder shall be required to contribute, in the aggregate,
any amount in excess of the amount by which the proceeds actually received by such Holder from the sale of the Registrable Securities
subject to the Proceeding exceeds the amount of any damages that such Holder has otherwise been required to pay by reason of such
untrue or alleged untrue statement or omission or alleged omission.  No person guilty of fraudulent misrepresentation (within
the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty
of such fraudulent misrepresentation.


 


The indemnity and contribution agreements
contained in this Section 6 are in addition to any liability that the Indemnifying Parties may have to the Indemnified Parties
and are not in diminution or limitation of the indemnification provisions under the Purchase Agreement.


 


SECTION 7.


MISCELLANEOUS


 


(a)   Piggy-Back Registrations.  If at any time during the Effectiveness Period, except as contemplated by Section 2(b) hereof,
there is not an effective Registration Statement covering all of the Registrable Securities and the Company shall determine to
prepare and file with the Commission a registration statement relating to an offering for its own account or the account of others
under the Securities Act of any of its equity securities, other than on Form S-4 or Form S-8 (each as promulgated under
the Securities Act) or their then equivalents relating to equity securities to be issued solely in connection with any acquisition
of any entity or business or equity securities issuable in connection with the stock option or other employee benefit plans, then
the Company shall send to each Holder a written notice of such determination and, if within 15 days after the date of such notice,
any such Holder shall so request in writing, the Company shall include in such registration statement all or any part of such Registrable
Securities such Holder requests to be registered; provided, however, that the Company shall not be required to register
any Registrable Securities pursuant to this Section 7(a) that are eligible for resale pursuant to Rule 144 promulgated
under the Securities Act without volume limitation and without current public information or that are the subject of a then effective
Registration Statement; provided, further, however, if there is not an effective Registration Statement covering all of the Registrable
Securities during the Effectiveness Period, the Company may file a registration statement with the Commission to register equity
securities of the Company to be sold on a primary basis, provided that the Company does not sell any such shares until there is
an effective Registration Statement covering all of the Registrable Securities. The Company shall have the right to terminate or
withdraw any registration initiated by it under this Section 7(a) prior to the effectiveness of such registration whether
or not the Holder has elected to include securities in such registration.


 






     


     


    

 


(b)   Discontinued Disposition.  The Holder agrees by its acquisition of such Registrable Securities that, upon receipt
of a notice from the Company of the occurrence of any event of the kind described in Section 3(c)(ii)-(vi), such Holder will
forthwith discontinue disposition of such Registrable Securities under the Registration Statement until such Holder’s receipt
of the copies of the supplemented Prospectus and/or amended Registration Statement or until it is advised in writing (the “Advice”)
by the Company that the use of the applicable Prospectus may be resumed, and, in either case, has received copies of any additional
or supplemental filings that are incorporated or deemed to be incorporated by reference in such Prospectus or Registration Statement;
provided that, with respect to the events described in Sections 3(c)(v) and 3(c)(vi), the Company shall not be entitled to
suspend the effectiveness or use of such Registration Statement for an aggregate of more than 45 consecutive Trading Days or an
aggregate of 90 Trading Days (which need not be consecutive) in any given 360-day period. The Company may provide appropriate stop
orders to enforce the provisions of this paragraph.


 


(c)   Compliance.  The Holder covenants and agrees that it will comply with the prospectus delivery requirements of
the Securities Act as applicable to it in connection with sales of Registrable Securities pursuant to the Registration Statement.


 


(d)   Furnishing of Information.  The Holder shall furnish in writing to the Company such information regarding itself,
the Registrable Securities held by it and the intended method of disposition of the Registrable Securities held by it, as shall
be reasonably requested by the Company to effect the registration of such Registrable Securities and shall execute such documents
in connection with such registration as the Company may reasonably request.


 


(e)   Termination of Registration Rights.  For the avoidance of doubt, it is expressly agreed and understood that
(i) in the event that there are no Registrable Securities outstanding as of a Filing Date, then the Company shall have no
obligation to file, caused to be declared effective or to keep effective any Registration Statement hereunder (including any Registration
Statement previously filed pursuant to this Agreement) and (ii) all registration rights granted to the Holders hereunder (including
the rights set forth in Section 7(a)), shall terminate in their entirety effective on the first date on which there shall
cease to be any Registrable Securities outstanding.


 


(f)    Waivers and Amendments.  No provision of this Agreement may be waived or amended except in a written instrument
signed by the Company and the Holder or Holders (as applicable) of no less than a majority of the then outstanding Registrable
Securities.  The Company shall provide prior notice to the Holder of any proposed waiver or amendment.  No waiver of
any default with respect to any provision, condition or requirement of this Agreement shall be deemed to be a continuing waiver
in the future or a waiver of any subsequent default or a waiver of any other provision, condition or requirement hereof, nor shall
any delay or omission of either party to exercise any right hereunder in any manner impair the exercise of any such right.


 


(g)   Governing Law; Submission to Jurisdiction.  All questions concerning the construction, validity, enforcement
and interpretation of this Agreement shall be governed by and construed and enforced in accordance with the internal laws of the
State of New York, without regard to the principles of conflicts of law thereof.  Each party agrees that all legal proceedings
concerning the interpretations, enforcement and defense of the transactions contemplated by this Agreement and any other Transaction
Documents (whether brought against a party hereto or its respective affiliates, directors, officers, shareholders, employees or
agents) shall be commenced exclusively in the state and federal courts sitting in the County of New York, in the State of New York.
Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the County of New
York, in the State of New York, for the adjudication of any dispute hereunder or in connection herewith or with any transaction
contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents), and hereby
irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to
the jurisdiction of any such court, that such suit, action or proceeding is improper or is an inconvenient venue for such proceeding. 
Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action
or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such
party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient
service of process and notice thereof.  Nothing contained herein shall be deemed to limit in any way any right to serve process
in any other manner permitted by law.


 






     


     


    

 


(h)   Remedies.  In the event of a breach by the Company or by the Holder of any of their obligations under this Agreement,
such Holder or the Company, as the case may be, in addition to being entitled to exercise all rights granted by law and under this
Agreement, including recovery of damages, will be entitled to specific performance of its rights under this Agreement.  The
Company and the Holder agree that monetary damages would not provide adequate compensation for any losses incurred by reason of
a breach by it of any of the provisions of this Agreement and hereby further agree that, in the event of any action for specific
performance in respect of such breach, it shall waive the defense that a remedy at law would be adequate.  The remedies provided
herein are cumulative and not exclusive of any remedies provided by law.


 


(i)    Notices.  All notices, requests, consents and other communications hereunder shall be in writing, shall be sent
by confirmed facsimile or electronic mail, or mailed by first-class registered or certified airmail, or nationally recognized overnight
express courier, postage prepaid, and shall be deemed given when so sent in the case of facsimile or electronic mail transmission,
or when so received in the case of mail or courier, and addressed as follows:


 





	 	if
to the Company, to: 	ClearSign Combustion Corporation



12870 Interurban Avenue South


Seattle, WA 98168


Attention: Chief Executive Officer


E-Mail: Steve.Pirnat@clearsign.com


Facsimile: 206.673.4848


 





	 	with a copy (which shall not constitute
notice) to:	Mitchell Silberberg & Knupp LLP



12 East 49th Street, 30th Floor


New York, NY 10017


Attn.: Melanie Figueroa, Esq.


E-Mail: mxf@msk.com


Facsimile: 212.509.7239


 


	 	if to the Investor, to:	GPclirSPV LLC



119
Warren Ave


3rd
Floor


Spring
Lake, NJ 07762


Attention:
Robert T. Hoffman Sr.


E-Mail:
rhoffman@princetonopp.com


 





	 	with copies (which shall not constitute
notice) to:	Bressler, Amery & Ross



325
Columbia Turnpike


Florham
Park, NJ 07932


Attention:
Kim Larsen


E-Mail:
Klarsen@bressler.com


 


or to such other person, at such other place
or in such manner as one party shall designate to other party in writing.


 






     


     


    

 


(j)    Successors and Assigns.  This Agreement shall inure to the benefit of and be binding upon the successors and
permitted assigns of each of the parties and shall inure to the benefit of the Holder.  The Company may not assign its rights
or obligations hereunder without the prior written consent of the Holder or Holders (as applicable) of a majority of the then outstanding
Registrable Securities (other than by merger or consolidation or to an entity which acquires the Company including by way of acquiring
all or substantially all of the Company’s assets). The rights of the Holder hereunder, including the right to have the Company
register Registrable Securities pursuant to this Agreement, may be assigned by the Holder to a transferee of such Holder, but only
if (i) such Holder agrees in writing with such transferee to assign such rights and related obligations under this Agreement,
and for such transferee to assume such obligations, and a copy of such agreement is furnished to the Company, (ii) the Company
is furnished with written notice of the name and address of such transferee and the securities with respect to which such registration
rights are being transferred or assigned, (iii) such transferee agrees in writing with the Company to be bound by all of the
provisions contained herein, and (iv) such transferee is an “accredited investor,” as that term is defined in
Rule 501 of Regulation D.


 


(k)   Headings. 
The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.


 


(l)    Severability.  If any term, provision, covenant or restriction of this Agreement is held by a court of competent
jurisdiction to be invalid, illegal, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions
set forth herein shall remain in full force and effect and shall in no way be affected, impaired or invalidated, and the parties
hereto shall use their reasonable best efforts to find and employ an alternative means to achieve the same or substantially the
same result as that contemplated by such term, provision, covenant or restriction.  It is hereby stipulated and declared to
be the intention of the parties that they would have executed the remaining terms, provisions, covenants and restrictions without
including any of such that may be hereafter declared invalid, illegal, void or unenforceable.


 


(m)  Counterparts.  This Agreement may be executed in any number of counterparts, each of which when so executed
shall be deemed to be an original and, all of which taken together shall constitute one and the same Agreement.


 


(n)   Use of Terms.  The parties agree and acknowledge that when, in this Agreement, the Company is required to use
its reasonable best efforts to perform any covenant under this Agreement, such requirement shall not obligate the Company, in the
reasonable judgment of the disinterested members of its Board of Directors, to perform any act that will have a material adverse
effect on the Company.


 


[signature page follows]


 




     


     


    

 


IN WITNESS WHEREOF, the parties have
executed this Registration Rights Agreement as of the date first written above.


 


	 	COMPANY:
	 	 
	 	CLEARSIGN COMBUSTION CORPORATION
	 	 
	 	By:	/s/ Stephen E. Pirnat
	 	Name:  
	Stephen E. Pirnat
	 	Title:	Chief Executive Officer
	 	 
	 	 
	 	INVESTOR:
	 	 
	 	CLIRSPV, LLC
	 	By: GPCLIRSPV LLC
	 	Its Manager
	 	 
	 	By:	/s/Robert T. Hoffman Sr.
	 	Name: 	Robert T. Hoffman Sr.
	 	Title:	Managing Member


 






     


     


    

 


REGISTRATION RIGHTS
AGREEMENT


 


 


ANNEX A


 


PLAN OF DISTRIBUTION


 


The selling stockholder and any of its pledgees,
donees, transferees, assignees or other successors-in-interest may, from time to time, sell, transfer or otherwise dispose of any
or all of their shares of common stock or interests in shares of common stock on any stock exchange, market or trading facility
on which the shares are traded or in private transactions.  These dispositions may be at fixed prices, at prevailing market
prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale,
or at negotiated prices.  The selling stockholder may use one or more of the following methods when disposing of the shares
or interests therein:


 


		·	ordinary brokerage transactions and transactions in
which the broker-dealer solicits purchasers;



 


		·	block trades in which the broker-dealer will attempt
to sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;



 


		·	through brokers, dealers or underwriters that may act
solely as agents;



 


		·	purchases by a broker-dealer as principal and resale
by the broker-dealer for its account;



 


		·	an exchange distribution in accordance with the rules of
the applicable exchange;



 


		·	privately negotiated transactions;



 


		·	through the writing or settlement of options or other
hedging transactions entered into after the effective date of the registration statement of which this prospectus is a part, whether
through an options exchange or otherwise;



 


		·	broker-dealers may agree with the selling stockholder
to sell a specified number of such shares at a stipulated price per share;



 


		·	one or more underwritten offerings on a firm commitment
or best efforts basis;



 


		·	a combination of any such methods of disposition; and



 


		·	any other method permitted pursuant to applicable law.



 


The selling stockholder may also sell shares
under Rule 144 under the Securities Act of 1933, as amended, or Securities Act, if available, rather than under this prospectus.


 


Broker-dealers engaged by the selling stockholder
may arrange for other broker-dealers to participate in sales.  Broker-dealers may receive commissions or discounts from the
selling stockholder (or, if any broker-dealer acts as agent for the purchaser of shares, from the purchaser) in amounts to be negotiated. 
The selling stockholder does not expect these commissions and discounts to exceed what is customary in the types of transactions
involved.


 


The selling stockholder may from time to
time pledge or grant a security interest in some or all of the shares of common stock owned by its and, if it defaults in the performance
of its secured obligations, the pledgees or secured parties may offer and sell shares of common stock from time to time under this
prospectus, or under a supplement or amendment to this prospectus under Rule 424(b)(3) or other applicable provision
of the Securities Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest
as selling stockholders under this prospectus.


 





     


     


    

 


Upon being notified in writing by the selling
stockholder that any material arrangement has been entered into with a broker-dealer for the sale of common stock through a block
trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer, we will file a supplement
to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, disclosing (i) the name of such
selling stockholder and of the participating broker-dealer(s), (ii) the number of shares involved, (iii) the price at
which such shares of common stock were sold, (iv) the commissions paid or discounts or concessions allowed to such broker-dealer(s),
where applicable, (v) that such broker-dealer(s) did not conduct any investigation to verify the information set out
or incorporated by reference in this prospectus, and (vi) other facts material to the transaction.  In addition, upon
being notified in writing by the selling stockholder that a donee or pledge intends to sell more than 500 shares of common stock,
we will file a supplement to this prospectus if then required in accordance with applicable securities law.


 


The selling stockholder also may transfer
the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will
be the selling beneficial owners for purposes of this prospectus.


 


In connection with the sale of the shares
of common stock or interests in shares of common stock, the selling stockholder may enter into hedging transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions, which
may in turn engage in short sales of the common stock in the course of hedging the positions they assume.  The selling stockholder
may also sell shares of common stock short after the effective date of the registration statement of which this prospectus is a
part and deliver these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that
in turn may sell these securities.  The selling stockholder may also enter into option or other transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions or the
creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of
shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus
(as supplemented or amended to reflect such transaction).


 


The selling stockholder and any broker-dealers
or agents that are involved in selling the shares may be deemed to be “underwriters” within the meaning of the Securities
Act in connection with such sales.  In such event, any commissions received by such broker-dealers or agents and any profit
on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. 
The maximum commission or discount to be received by any member of the Financial Industry Regulatory Authority (FINRA) or independent
broker-dealer will not be greater than 8% of the initial gross proceeds from the sale of any security being sold.


 


We have advised the selling stockholder
that it is required to comply with Regulation M promulgated under the Securities Exchange Act during such time as it may be engaged
in a distribution of the shares.  The foregoing may affect the marketability of the common stock.


 


The aggregate proceeds to the selling stockholder
from the sale of the common stock offered by it will be the purchase price of the common stock less discounts or commissions, if
any.  The selling stockholder reserves the right to accept and, together with its agents from time to time, to reject, in
whole or in part, any proposed purchase of common stock to be made directly or through agents.  We will not receive any of
the proceeds from this offering.


 


We are required to pay all fees and expenses
incident to the registration of the shares.  We have agreed to indemnify the selling stockholder against certain losses, claims,
damages and liabilities, including liabilities under the Securities Act or otherwise.


 


We have agreed with the selling stockholder
to keep the registration statement of which this prospectus constitutes a part effective until the earlier of (a) such time
as all of the shares covered by this prospectus have been disposed of pursuant to and in accordance with the registration statement,
and (b) the date on which the shares of common stock covered by this prospectus may be sold by non-affiliates without any
volume or manner of sale restrictions or current public information pursuant to Rule 144 of the Securities Act.


 






     


     


    

 


APPENDIX II


 


SELLING STOCKHOLDER
QUESTIONNAIRE








 






     


     


    

 


SELLING STOCKHOLDER NOTICE AND QUESTIONNAIRE


 


	 	 
	 	Name of Selling Stockholder (please print)


 


CLEARSIGN COMBUSTION CORPORATION


QUESTIONNAIRE FOR SELLING STOCKHOLDERS


 


IMPORTANT:  IMMEDIATE ATTENTION
REQUIRED


 


This Questionnaire is being furnished to
all persons or entities (the “Purchasers”) who purchased shares of Common Stock (“Common Stock”) of ClearSign
Combustion Corporation (the “Company”) pursuant to the Stock Purchase Agreement by and among the Company and the Purchaser
(the “Purchase Agreement”).  This Questionnaire relates to certain information required to be disclosed in the
Registration Statement on Form S-3 (the “Registration Statement”) to be prepared by the Company for filing with
the United States Securities and Exchange Commission (the “SEC”) pursuant to the Registration Rights Agreement entered
into by and among the Company and the Purchaser (the “Registration Rights Agreement”) in connection with the Purchase
Agreement.  The Company must receive a completed Questionnaire from each Purchaser in order to include such Purchaser’s
shares of Common Stock in the Registration Statement.


 


The furnishing of accurate and complete
responses to the questions posed in this Questionnaire is an extremely important part of the registration process.  The inclusion
of inaccurate or incomplete disclosures in the Registration Statement can result in potential liabilities, both civil and criminal,
to the Company and to the individuals who furnish the information.  Accordingly, Purchaser is advised to consult its own securities
law counsel regarding the consequences of being named or not being named as a selling securityholder in the Registration Statement
and related prospectus.


 


PLEASE GIVE A RESPONSE TO EVERY QUESTION,
indicating “None” or “Not Applicable” where appropriate.  Please complete, sign, and return
one copy of this Questionnaire by facsimile, email or overnight courier as soon as possible.


 


Unless stated otherwise, answers should
be given as of the date you complete this Questionnaire.  However, it is your responsibility to inform us of any changes that
may occur to your situation.  If there is any situation about which you have any doubt, or if you are uncertain as to the
meaning of any terms used in this Questionnaire, please contact [                      ]


 


PART I - STOCK OWNERSHIP


 


		Item 1.	Beneficial Ownership.



 


a.  Deemed Beneficial Ownership. 
Please state the amount of securities of the Company you own on the date you complete this Questionnaire.  (If none, please
so state in each case.)


 






     


     


    

 


	 	 	Number of Shares of
	Amount Beneficially Owned(1)	 	Common Stock Owned
	 	 	 
	Please state the number of shares owned by you or by family members, trusts and other organizations with which you have a relationship, and any other shares of which you may be deemed to be the “beneficial owner”(1):	 	 
	 	 	 
	Total Shares:	 	 
	 	 	 
	Of such shares:	 	 
	 	 	 
	Shares as to which you have sole voting power:	 	 
	 	 	 
	Shares as to which you have shared voting power:	 	 
	 	 	 
	Shares as to which you have sole investment power:	 	 
	 	 	 
	Shares as to which you have shared investment power:	 	 
	 	 	 
	Shares which you will have a right to acquire before 60 days after the date you complete this questionnaire through the exercise of options, warrants or otherwise:	 	 


 


Do you have any present plans to exercise
options or otherwise acquire, dispose of or to transfer shares of Common Stock of the Company between the date you complete this
Questionnaire and the date which is 60 days after the date in which the Registration Statement is filed?


 


Answer:


 


If so, please describe.


 


b.             Pledged Securities.  If any of such securities have been pledged or otherwise deposited as collateral or are the subject
matter of any voting trust or other similar agreement or of any contract providing for the sale or other disposition of such securities,
please give the details thereof.


 


Answer:


 


c.             Disclaimer of Beneficial Ownership.  Do you wish to disclaim beneficial ownership(1) of any of the shares reported
in response to Item 1(a)?


 


Answer:


 


If the answer is “Yes”, please
furnish the following information with respect to the person or persons who should be shown as the beneficial owner(s)(1) of
the shares in question.


 


	Name and Address of	 	Relationship of	 	Number of Shares
	Actual Beneficial Owner	 	Such Person To You	 	Beneficially Owned
	 	 	 	 	 
	 	 	 	 	 
	 	 	 	 	 


 






     


     


    

 


d.             Shared Voting or Investment Power over Securities.  Will any person be deemed to have beneficial ownership over any
of the Securities purchased by you pursuant to the Purchase Agreement?


 


Answer:


 


If the answer is “Yes”, please
furnish the following information with respect to the person or persons who should be shown as the beneficial owner(s)(1) of
the Securities in question.


 


	Name and Address of	 	Relationship of	 	Number of Shares
	Beneficial Owner	 	Such Person To You	 	Beneficially Owned
	 	 	 	 	 
	 	 	 	 	 
	 	 	 	 	 


 


Item 2.  Major Shareholders. 
Please state below the names of persons or groups known by you to own beneficially(1) more than 5% of the Company’s
Common Stock.


 


Answer:


 


Item 3.  Change of Control. 
Do you know of any contractual arrangements, including any pledge of securities of the Company, the operation of which may at a
subsequent date result in a change of control of the Company?


 


Answer:


 


Item 4.  Relationship with
the Company.  Please state the nature of any position, office or other material relationship you have, or have had within
the past three years, with the Company or its affiliates.


 


	 	 	Nature of
	Name	 	Relationship
	 	 	 
	 	 	 
	 	 	 


 


Item 5.  Broker-Dealer Status. 
Is the Purchaser a broker-dealer registered pursuant to Section 15 of the Securities Exchange Act of 1934, as amended (the
“Exchange Act”)?


 


		 ̈	Yes.



 


		 ̈	No.



 


If so, please answer the remaining questions
under this Item 5.


 


Note that the Company will be required
to identify any registered broker-dealer as an underwriter in the Registration Statement and related prospectus.


 


a.             If the Purchaser is a registered broker-dealer, please indicate whether the Purchaser purchased its Common Stock for investment
or acquired them as transaction-based compensation for investment banking or similar services.


 


Answer:


 






     


     


    

 


Note that if the Purchaser is a registered
broker-dealer and received its Common Stock other than as transaction-based compensation, the Company is required to identify the
Purchaser as an underwriter in the Registration Statement and related prospectus.


 


b.             Is the Purchaser an affiliate of a registered broker-dealer? For purposes of this Question, an “affiliate” of a specified
person or entity means a person or entity that directly, or indirectly through one or more intermediaries, controls or is controlled
by, or is under common control with, the person or entity specified.


 


		 ̈	Yes.



 


		 ̈	No.



 


If so, please answer questions (i)-(iii) below
under this Item 5(b).


 


i.              Please describe the affiliation between the Purchaser and any registered broker-dealers:


 


ii.             If the Common Stock was received by the Purchaser other than in the ordinary course of business, please describe the circumstances:


 


iii.            If the Purchaser, at the time of its receipt of Common Stock, has had any agreements or understandings, directly or indirectly,
with any person to distribute the Common Stock, please describe such agreements or understandings:


 


Note that if the Purchaser is an affiliate
of a broker-dealer and did not receive its Common Stock in the ordinary course of business or at the time of receipt
had any agreements or understandings, directly or indirectly, to distribute the securities, the Company must identify the Purchaser
as an underwriter in the Registration Statement and related prospectus.


 


Item 6.  Nature of Beneficial
Holding.  The purpose of this question is to identify the ultimate natural person(s) or publicly held entity that
exercise(s) sole or shared voting or dispositive power over the Registrable Securities (as defined in the Registration Rights
Agreement).


 


a.             Is the Purchaser a natural person?


 


		 ̈	Yes.



 


		 ̈	No.



 


b.             Is the Purchaser required to file, or is it a wholly owned subsidiary of a company that is required to file, periodic and other
reports (for example, Form 10-K, 10-Q, 8-K) with the SEC pursuant to Section 13(a) or 15(d) of the Exchange
Act?


 


		 ̈	Yes.



 


		 ̈	No.



 


c.             Is the Purchaser an investment company, or a subsidiary of an investment company, registered under the Investment Company Act of
1940, as amended?


 


		o	Yes.



 


		o	No.



 


If a subsidiary, please identify the publicly
held parent entity:


 






     


     


    

 


d.             If you answered “no” to questions (a), (b) and (c) above, please identify the controlling person(s) of
the Purchaser (the “Controlling Entity”). If the Controlling Entity is not a natural person or a publicly held entity,
please identify each controlling person(s) of such Controlling Entity. This process should be repeated until you reach natural
persons or a publicly held entity that exercises sole or shared voting or dispositive power over the Registrable Securities:


 


***PLEASE NOTE THAT THE SEC REQUIRES
THAT THESE NATURAL PERSONS BE NAMED IN THE PROSPECTUS***


 


PART II - CERTAIN TRANSACTIONS


 


Item 7.  Transactions with
the Company.  If you, any of your associates(2), or any member of your immediate family(3) had or will have any direct
or indirect material interest in any transactions(4) or series of transactions to which the Company or any of its subsidiaries
was a party at any time since January 1, 2015, or in any currently proposed transactions or series of transactions in which
the Company or any of its subsidiaries will be a party, in which the amount involved exceeds $120,000, please specify (a) the
names of the parties to the transaction(s) and their relationship to you, (b) the nature of the interest in the transaction,
(c) the amount involved in the transaction, and (d) the amount of the interest in the transaction.  If the answer
is “none”, please so state.


 


Answer:


  


Item 8.  Third Party Payments. 
Please describe any compensation paid to you by a third party pursuant to any arrangement between the Company and any such third
party.


 


Answer:


 


PART III — PLAN OF DISTRIBUTION


 


The selling stockholder and any of its pledgees,
donees, transferees, assignees or other successors-in-interest may, from time to time, sell, transfer or otherwise dispose of any
or all of their shares of common stock or interests in shares of common stock on any stock exchange, market or trading facility
on which the shares are traded or in private transactions.  These dispositions may be at fixed prices, at prevailing market
prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale,
or at negotiated prices.  The selling stockholder may use one or more of the following methods when disposing of the shares
or interests therein:


 


		·	ordinary brokerage transactions and transactions in
which the broker-dealer solicits purchasers;



 


		·	block trades in which the broker-dealer will attempt
to sell the shares as agent but may position and resell a portion of the block as principal to facilitate the transaction;



 


		·	through brokers, dealers or underwriters that may act
solely as agents;



 


		·	purchases by a broker-dealer as principal and resale
by the broker-dealer for its account;



 


		·	an exchange distribution in accordance with the rules
of the applicable exchange;



 


		·	privately negotiated transactions;



 


		·	through the writing or settlement of options or other
hedging transactions entered into after the effective date of the registration statement of which this prospectus is a part, whether
through an options exchange or otherwise;



 


		·	broker-dealers may agree with the selling stockholder
to sell a specified number of such shares at a stipulated price per share;



 






     


     


    

 


		·	one or more underwritten offerings on a firm commitment
or best efforts basis;



 


		·	a combination of any such methods of disposition; and



 


		·	any other method permitted pursuant to applicable law.



 


The selling stockholder may also sell shares
under Rule 144 under the Securities Act of 1933, as amended, or Securities Act, if available, rather than under this prospectus.


 


Broker-dealers engaged by the selling stockholder
may arrange for other broker-dealers to participate in sales.  Broker-dealers may receive commissions or discounts from the
selling stockholder (or, if any broker-dealer acts as agent for the purchaser of shares, from the purchaser) in amounts to be negotiated. 
The selling stockholder does not expect these commissions and discounts to exceed what is customary in the types of transactions
involved.


 


The selling stockholder may from time to
time pledge or grant a security interest in some or all of the shares of common stock owned by its and, if it defaults in the performance
of its secured obligations, the pledgees or secured parties may offer and sell shares of common stock from time to time under this
prospectus, or under a supplement or amendment to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities
Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling stockholders
under this prospectus.


 


Upon being notified in writing by the selling
stockholder that any material arrangement has been entered into with a broker-dealer for the sale of common stock through a block
trade, special offering, exchange distribution or secondary distribution or a purchase by a broker or dealer, we will file a supplement
to this prospectus, if required, pursuant to Rule 424(b) under the Securities Act, disclosing (i) the name of such selling stockholder
and of the participating broker-dealer(s), (ii) the number of shares involved, (iii) the price at which such shares of common stock
were sold, (iv) the commissions paid or discounts or concessions allowed to such broker-dealer(s), where applicable, (v) that such
broker-dealer(s) did not conduct any investigation to verify the information set out or incorporated by reference in this prospectus,
and (vi) other facts material to the transaction.  In addition, upon being notified in writing by the selling stockholder
that a donee or pledge intends to sell more than 500 shares of common stock, we will file a supplement to this prospectus if then
required in accordance with applicable securities law.


 


The selling stockholder also may transfer
the shares of common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will
be the selling beneficial owners for purposes of this prospectus.


 


In connection with the sale of the shares
of common stock or interests in shares of common stock, the selling stockholder may enter into hedging transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions, which
may in turn engage in short sales of the common stock in the course of hedging the positions they assume.  The selling stockholder
may also sell shares of common stock short after the effective date of the registration statement of which this prospectus is a
part and deliver these securities to close out their short positions, or loan or pledge the common stock to broker-dealers that
in turn may sell these securities.  The selling stockholder may also enter into option or other transactions after the effective
date of the registration statement of which this prospectus is a part with broker-dealers or other financial institutions or the
creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of
shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus
(as supplemented or amended to reflect such transaction).


 


The selling stockholder and any broker-dealers
or agents that are involved in selling the shares may be deemed to be “underwriters” within the meaning of the Securities
Act in connection with such sales.  In such event, any commissions received by such broker-dealers or agents and any profit
on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. 
The maximum commission or discount to be received by any member of the Financial Industry Regulatory Authority (FINRA) or independent
broker-dealer will not be greater than 8% of the initial gross proceeds from the sale of any security being sold.


 






     


     


    

 


We have advised the selling stockholder
that it is required to comply with Regulation M promulgated under the Securities Exchange Act during such time as it may be engaged
in a distribution of the shares.  The foregoing may affect the marketability of the common stock.


 


The aggregate proceeds to the selling stockholder
from the sale of the common stock offered by it will be the purchase price of the common stock less discounts or commissions, if
any.  The selling stockholder reserves the right to accept and, together with its agents from time to time, to reject, in
whole or in part, any proposed purchase of common stock to be made directly or through agents.  We will not receive any of
the proceeds from this offering.


 


We are required to pay all fees and expenses
incident to the registration of the shares.  We have agreed to indemnify the selling stockholder against certain losses, claims,
damages and liabilities, including liabilities under the Securities Act or otherwise.


 


We have agreed with the selling stockholder
to keep the registration statement of which this prospectus constitutes a part effective until the earlier of (a) such time as
all of the shares covered by this prospectus have been disposed of pursuant to and in accordance with the registration statement,
and (b) the date on which the shares of common stock covered by this prospectus may be sold by non-affiliates without any volume
or manner of sale restrictions or current public information pursuant to Rule 144 of the Securities Act.


 


*         *         *


 


The undersigned has reviewed the Plan of
Distribution set forth above and does not have a present intention of effecting a sale in a manner not described therein.


 


	 	 ̈	Agree	 ̈	Disagree	 
	 	 	(If left blank, response will be deemed to be “Agree”.)	 


 


The
undersigned hereby represents that the undersigned understands, pursuant to Securities Act Sections Compliance and Disclosure
Interpretations Section 239.10, a copy of which is attached hereto as Exhibit 1, that the undersigned may not make any short sale
of the Common Stock prior to the effectiveness of the Registration Statement, and further covenants to the Company that the undersigned
will not engage in any short sales of such stock to be registered under the Registration Statement prior to its effectiveness.





 






     


     


    

 


SIGNATURE


 


The undersigned understands that the Company
anticipates filing the Registration Statement within the time frame set forth in the Registration Rights Agreement.  If at
any time any of the information set forth in my responses to this Questionnaire has materially changed due to passage of time (other
than due to the receipt of the Common Stock set forth opposite the undersigned’s name in the Schedule of Purchasers in the
Purchase Agreement), or any development occurs which requires a change in any of my answers, or has for any other reason become
incorrect, the undersigned agrees to furnish as soon as practicable to the individual to whom a copy of this Questionnaire is to
be sent, as indicated and at the address shown on the first page hereof, any necessary or appropriate correcting information. 
Otherwise, the Company is to understand that the above information continues to be, to the best of my knowledge, information and
belief, complete and correct.


 


Upon any sale of Common Stock pursuant to
the Registration Statement, the undersigned hereby agrees to deliver to the Company and the Company’s transfer agent the
Certificate of Subsequent Sale set forth in Exhibit I hereto.


 


The undersigned understands that the information
that the undersigned is furnishing to the Company herein will be used by the Company in the preparation of the Registration Statement.


 


	 	Name of Purchaser:  	 
	 	 	 
	 	 	 
	Date:                                   , 201_	Signature:	 
	 	 	 
	 	 	 
	 	Print Name: 	 
	 	 	 
	 	 	 
	 	Title (if applicable): 	 
	 	 	 
	 	 	 
	 	Address: 	 
	 	 	 
	 	 	 


  


FOOTNOTES


 


		1.	Beneficial Ownership.  You are the beneficial
owner of a security, as defined in Rule 13d-3 under the Securities Exchange Act of 1934 (the “Exchange Act”), if you,
directly or indirectly, through any contract, arrangement, understanding, relationship or otherwise have or share: (1) voting
power, which includes the power to vote, or to direct the voting of, such security, and/or (2) investment power, which includes
the power to dispose, or to direct the disposition of, such security.  You are also the beneficial owner of a security if
you, directly or indirectly, create or use a trust, proxy, power of attorney, pooling arrangement or any other contract, arrangement
or device with the purpose or effect of divesting yourself of beneficial ownership of a security or preventing the vesting of
such beneficial ownership.



 


You are deemed to be the beneficial owner of a security
if you have the right to acquire beneficial ownership of such security at any time within 60 days including, but not limited
to, any right to acquire such security (a) through the exercise of any option, warrant or right, (b) through the conversion of
a security, or (c) pursuant to the automatic termination of, or the power to revoke a trust, discretionary account, or similar
arrangement.


 






     


     


    

 


Ordinarily, shares held in the name of your spouse
or minor child should be considered as beneficially owned by you absent special circumstances to indicate that you do not have,
as a practical matter, voting power or investment power over such shares.  Similarly, absent countervailing facts, securities
held in the name of relatives who share your home are to be reported as being beneficially owned by you.  In addition, securities
held for your benefit in the name of others, such as nominees, trustees and other fiduciaries, securities held by a partnership
of which you are a partner, and securities held by a corporation controlled by you should be regarded as beneficially owned by
you.


 


This definition of beneficial ownership is very broad;
therefore, even though you may not actually have or share voting or investment power with respect to securities owned by persons
in your family or living in your home, you should include such shares in your beneficial ownership disclosure and may then disclaim
beneficial ownership of such securities.


 


		2.	Associate.  The term “associate”,
as defined in Rule 14a-1 under the Exchange Act, means (a) any corporation or organization (other than the Company or any of its
majority owned subsidiaries) of which you are an officer or partner or are, directly or indirectly, the beneficial owner of 10%
or more of any class of equity securities, (b) any trust or other estate in which you have a substantial beneficial interest or
as to which you serve as trustee or in a similar capacity, and (c) your spouse, or any relative of yours or relative of your spouse
living in your home or who is a director or officer of the Company or of any subsidiary.  The term “relative of yours”
as used in this Questionnaire refers to any relative or spouse of yours, or any relative of such spouse, who has the same home
as you or who is a director or officer of any subsidiary of the Company.



 


Please identify your associate
referred to in your answer and indicate your relationship.


 


		3.	Immediate Family.  The members of your “immediate
family” are deemed to include the following:  your spouse; your parents; your children; your siblings; your mother-in-law
or father-in-law; your sons- and daughters-in-law; and your brothers- and sisters-in-law.



 


		4.	Transactions.  The term “transaction”
is to be understood in its broadest sense, and includes the direct or indirect receipt of anything of value.  Please note
that indirect as well as direct material interests in transactions are to be disclosed.  Transactions in which you would
have a direct interest would include your purchasing or leasing anything (stock in a business acquired by the Company, office
space, plants, Company apartments, computers, raw materials, finished goods, etc.) from or selling or leasing anything to, or
borrowing or lending cash or other property from or to, the Company, or any subsidiary.]



 




     


     


    

 


Exhibit I


 


CERTIFICATE OF SUBSEQUENT SALE


 


[Transfer Agent]


 


		RE:	Sale of Shares of Common Stock of ClearSign Combustion
Corporation (the “Company”) pursuant to the Company’s Prospectus dated                              ,
(the “Prospectus”)



 


Dear Sir/Madam:


 


The undersigned hereby certifies, in connection
with the sale of shares of Common Stock of the Company included in the table of Selling Stockholders in the Prospectus, that the
undersigned has sold the shares pursuant to the Prospectus and in a manner described under the caption “Plan of Distribution”
in the Prospectus and that such sale complies with all securities laws applicable to the undersigned, including, without limitation,
the Prospectus delivery requirements of the Securities Act of 1933, as amended.


 





	Selling Stockholder (the beneficial owner):  	 



 


	Record Holder (e.g., if held in name of nominee):  	 



 


	Book Entry Position or Restricted Stock Certificate No.(s):  	 



 


	Number of Shares Sold:  	 



 


	Date of Sale:  	 




 


In the event that you receive a stock certificate(s)
or evidence of a book entry position representing more shares of Common Stock than have been sold by the undersigned, then you
should return to the undersigned a newly issued certificate or book entry position for such excess shares in the name of the Record
Holder and BEARING A RESTRICTIVE LEGEND.  Further, you should place a stop transfer on your records with regard to
such certificate.  Notwithstanding the foregoing, in the event that the undersigned executes and delivers to you and to the
Company the certification set forth on Annex I, upon instructions from the Company, you should return to the undersigned a newly
issued certificate or book entry position for such excess shares of Common Stock in the name of the Record Holder without any restrictive
legend.  In addition, no subsequent certification will be required to be delivered to you by the undersigned provided that
the representations and warranties set forth on Annex I have been delivered to you and continue to be accurate.


 


	 	 	Very truly yours,
	 	 	 
	 	 	 
	Dated:  	 	 	By: 	 
	 	 	 
	 	 	 
	 	 	Print Name: 	 
	 	 	 
	 	 	 
	 	 	Title:  	 
	 	 	 	 	 	 	 


 


		cc:	ClearSign Combustion Corporation



[Address]


Attention:


 




     


     


    

 


Annex I


 


In connection with any excess shares to
be returned to the Selling Stockholder upon a sale of shares of Common Stock of ClearSign Combustion Corporation (the “Company”)
included in the table of Selling Stockholders in the Prospectus, the undersigned hereby certifies to the Company and [Transfer
Agent], that:


 


1.             In connection with the sale by the undersigned stockholder of any of the shares of Common Stock pursuant to the Prospectus, the
undersigned stockholder will deliver a copy of the Prospectus included in the Registration Statement to the purchaser directly
or through the undersigned stockholder’s broker-dealer in compliance with the requirements of the Securities Act of 1933
and the Securities Exchange Act of 1934.


 


2.             Any such sale will be made only in the manner described under “Plan of Distribution” in the Prospectus.


 


3.             The undersigned stockholder will only sell the shares of Common Stock while the Registration Statement is effective, unless another
exemption from registration is available.


 


4.             The Company and its attorneys may rely on this letter to the same extent as if it were addressed to them.


 


5.             The undersigned stockholder agrees to notify you immediately of any development or occurrence which to his, her or its knowledge
would render any of the foregoing representations and agreements inaccurate.


 


All terms not defined
herein are as defined in the Stock Purchase Agreement entered into in _______ 2018 between the Company and the Purchaser.


 


	 	 	Very truly yours,
	 	 	 
	 	 	 
	Dated:	 	 	By:  	 
	 	 	 
	 	 	 
	 	 	Print Name:  	      
	 	 	 
	 	 	 
	 	 	Title:  	 
	 	 	 	 	 	 	 


 ]